Electronic piano



June. 28, 1960 B. F. MlEssNER ELECTRONIC PIANO 3 Sheets-Sheet 1 FiledAug. 14, 1957 INVENTOR mzzEMressnez Jun Filed Aug. 14, 1957 e 28, 1960B. F. MlEssNl-:R

ELECTRONIC PIANO 3 Sheets-#Sheet 2 INVENTOR June 28, 1960 B. MIESSN ERELECTRONIC PIANO 3 Sheets-Sheet 3 Filed Aug. 14, 1957OOOOOOOOOOOOOOOOOODO QOOOOOOOOOOOQOOOOOOC000000 l INVENTOR .Ben I /71z'n .Z'Messner' BY I 'fr ATTORNEY United States Patent ELECTRONIC PIANOBenjamin F. Miessner, Harding Township, Morris County,I

' NJ., assgnor, by mesne assignments, to The Wurlitzer Company, Chicago,Ill., a corporation of Ohio Filed Aug. 14, 1957, Ser. No. 678,101

Claims. (Cl. 84-1.14)

present invention is the provision of an improved such instrument.

In the use of reeds instead of strings a problem is presented by theinharmonicity of the relationship of the upper partials (i.e., all abovethe first, or fundamental) of the vibration to the fundamentalwhereas itis a requisite of the output tone that it contain very small developmentof inharmonic partials and a rich development of harmonic ones. Anobject of this invention is the provision of a solution to this problem.

In a tone produced by a conventional piano there is a strong initialburst, including a rich harmonic development, followed in the very earlyinstants by an apparent rapid amplitude decay or decrement. Heretoforein electronic instruments utilizing reeds as the vibrators such earlyrapid decrement has been lacking-or even reversed, into a slight initialincrement. An object of this invention is to minimize such increment orto increase such decrement in the reed type of instrument. An alliedobject is to approximate the early rapid decrement characteristic of aconventional piano.

Another object is the provision of improved arrangements of translatingdevice, or pick-up, with reed.

Other and allied objects will more fully appear from the followingdescription and the appended claims:

This application is a continuation-in-part of' my copending applicationSerial No. 485,471 filed February 1, 1955, now abandoned.

This application discloses and claims subject matter disclosed in mycopending application Serial No. 485,471, filed February 1, 1955,subject matter disclosed in my copending application 255,383, filedNovember 8, 1951, and subject matter disclosed in my copendingapplication Serial No. 169,714, filed June 22, 1950, now abandoned.

In the description of my invention hereinafter set forth reference ishad to the accompanying drawings, of which:

Figure 1 is a vertical sectional view of an electronic piano embodyingmy invention in one form (line 1-1 in Figure 2 indicating the planealong which Figure 1 is taken);

Figure 2 is a horizontal view taken looking upwardly toward the planeindicated by the line 2-2 of Figure 1 (or a vertical view seen whenlooking rearwardly toward the cover 6 of the instrument when the coveris in raised position) and, for simplicity, showing only a few of thereeds 10;

Figure 3 is an enlarged vertical view, in section, taken along the line3 3 of Figure 1;

Figure 3a is an enlarged fragmentary view of a portion of Figure 4;

ICC

Figure 4 is a horizontal sectional view taken along line 4-4 of Figure3;

Figure 4a is an enlarged sectional View taken along line 4a--4a ofFigure 4; Y

Figure 5 is a horizontal sectional View taken along line 5-5 of Figure3;

Figure 6 is an enlarged fragmentary view, partly in section, of aportion of Figure 1;

Figure 7 is a horizontal sectional view line 7-7 of Figure 6;

Figure 8 is an enlarged view of a righthand portion of Figure 2;

Figure 9 is a partial plan view of the instrument as seen when the cover6 is raised, showing for simplicity only a few of the hammers 11, keys20 and dampers 56;

Figure 10 is a schematic showing of the early portions of the electronicsystem of the instrument;

Figure l1 is a vertical sectional view of a base, reed and pick-upembodying my invention in another form;

Figure 12 is a perspective view of the pick-up structure of Figure 11;

Figure 13 is a front view of a portion of the assembly of Figure 1lillustrating a readjustment of the pick-up structure relative to thereed; and

Figure 14 is a perspective view of a number of reeds and pick-upsembodying my inventionin still another taken along j form.

The drawings illustrate a 73-note instrument, but it will be understoodthat this is by way of illustration only.

In Figure 1 the elements 1, 2, 3 and 4 respectively represent righthandand, back, bottom and front portions of the cabinet for the instrument,these portions together with the lefthand end portion (not shown) beingfor example permanently secured together. A removable sloping fall board5 may extend between the two end portions, while a cover 6 may be hingedat its rear to the top of the back portion 2. As disclosed in connectionwith such a cabinet in my copending application Serial No. 169,714abovementioned, the reeds and pickups may be carried by the bottom ofthe cover 6, the hammers may be supported by the back portion 2, and thehammer-actuating keys may be supported on the bottom portion 3.

The reeds appear as 10; their mounting, the translation of theirvibrations, and related matters are set forth 1n detail hereinafter. Theexcitation of each reed is by a respective hammer 11 positionedtherebelow, the head 12 of the hammer being propellable upwardly tostrike the reed (typically, at approximately the mid-reed nodal pointfor the third partial vibrating of the reed, as hereinafter mentioned).The hammer head 12 may consist of a chisel-shaped block of wood,preferably covered with felt, or sponge rubber, of progressively greaterthickness the lower the frequency of the associated reed. The head 12 isaffixed to the forward extremity of a shank 13, which is preferably ofrectangular cross section with the major dimension of that sectionvertically disposed. The rear extremity of the shank 13 is in turnsecured in the butt 14, which is pivoted at 18 to the flange 15. All theflanges `15 are secured on top of a transverse rail 16 fixed to andextending forwardly from the cabinet back 2.

It may be mentioned that the material of the covering of the hammer headmay desirably be characterized by some viscosity, to aid in the dampingof upper partials of the reed vibration during they short period ofhammerhead vcontact with the reed.

Each hammer is propelled to strike the respective reed by a respectivekey 20, acting through a respective coupling member 30. The keys 20 maybe pivoted about conventional pins 21, each key resting on a stack 22 ofwashers surrounding its respective pin, and may beV guided byconventional nfront guide pins 23 each surrounded by a conventionalstack 24 of washers forming a front-end downstop. The rear end of eachkey is bifurcated by a vertical `'slot 25 (see Figure 9), which freelyembraces a respective post 26 screwed into the :.Qabinetfbottom 31 andhaving an ,enlarged :head A2,7 immediately .underwhich may be provided athin slightly viscous and elastic washer 2.3; the head `2,77 and washerA2 8 form `an upstop lfor the rear end of the respective key. Therelative adjustments of this rear-end tupstop ,27--28 (-eiected -by|#rotation of post 26) and of the liront-.end downstop 4(effected bychoice of washer thicknesses) .agresuch that'gwhen ;thefkey is operatedthe primarily effective :stoptis the rear-.end ilusion 27e-28emefrontend dewnstop .being a secondary one whose function is to limitdeformation xof the key which may result from front-end linger pressurelcon- -tvinued after the ,rearqend upstop has `acted.

,Near its rear extremity each vkey carries ;a respective capstan member`31 screwed into ithe key (fully seen in Figure 6). A little above thekeystop -this member may have the enlarged khex portion 32 engageable bya wrench for vertical adjustment of the capstan member .-31. ,Bromthehexportion 32 upwardly the capstan member I3.1 may consist of a rod33 preferably quite smoothly Cylindrical `excepting fora .longitudinal-ilat 34 several thousandths cf .an ,inch wide (shown in exaggeratedwidth in Figure 6).

Ihe respective ,coupling member 3.0 .may comprise a vertically disposedcylinder 3G having, upwardly from its bottom, a circular central boreclosely tting -about ltherod 33 (excepting for the flat 34 ot thelatter) but slidable therealong (which action ,may be Vaidedv by a light.film Aof .silicone grease on the rod), the upper end ofthe member ,30being solid and exteriorly rounded into substantially 4hemisphericalconfiguration. Normally the lower extremity of the cylinder 30 rests onthe capstan hex lportion 32, if desired through the intermediary of aquite thin slightly viscous Aand elastic washer 35-and when the cylinder30 so rests the vair-chamber 36, formed between lthe bore .of thecylinder and vrod 33 at the top of the latter, may be of quite smallvertical dimension. Nor- Inlly un the upper end Vof each coupling member30 rests the forward portion of .the respective hammer butt 14., ifdesired through the intermediary of `a quite thin layer 17 of slightlyviscous and .elastic material `secured -to the bottom of the hammerbutt. When the respective lharnmer butt so rests the lower extremity ofthe respective vhammer head 12 is preferably slightly lspaced above avfelt pad 29 `secured therebelow on the top of the respecy.tive key 20-Qperation of the key 20 (i.e., depression of its forward extremity bythe linger), if carried out extremely slowly, will of course raise thecapstan member 31 and coupling member 3.9 Without disturbance of thenormal 'interrelationship between the latter members, and will swing thehammer upwardly about its pivot without any breaking of the contact ofthe hammer but with Vthe coupling member. Preferably the components areso geometrically interrelated that this raising will continue to, but bestopped (by the upstop 27-28), at, a position of the hammer headslightly spaced from the bottom of the respective reed 10. No impact ofhammer head with reed will occur-just as there occurs in theconventional piano no hammer-string impact when the key is extremelyslowly operated. When, however, the key 20 lis operated with anysubstantial velocity, its own sudden stoppage by the upstop 27-28 willnot be accompanied by stoppage of either the coupling member 3i) or thelhammer 11. The hammer will continue under 4its own momentum, and withvnegligible change in velocity,

,to strike and rebounddownwardly ,from the reed. Correspondingly thecoupling member 30 will ycontinue up- Wardly under its own momentumbutinthe case of this member there is a substantial and steady loss ofvelocity, since this coupling-member movement can only tion.

4 occur with an enlargement of the air chamber 36, which can only occurwith a tlow of air thereinto along the narrow passage formed between thebore of the coupling member 30 and the flat 34, which in turn involvessubstantial energy dissipation through air friction.

Assuming the key remains `operated and the capstan member 31 thus in anelevated position, then in the rela* tively high-velocity Arebound of.the hammer from the reed its downwardly moving butt 14 will quicklycome into impact fftlntoug'h '17 if employed) against the :stillrising'but Vnow relatively low-velocity Vcoupling member 30. I have found itdesirable to make the mass of the coupling member several times theefectivemass of the hammer (i.e., the hammer mass as seen at the regionof contact betweenhammer and coupling member). If this be done, theconditions .at the time of impact will be such that at the instant afterimpac-t the hammer velocity will be `very small, `while the couplingmember will possess most .of .the kinetic energy previously in therebounding hammer and will 1itself. befin downward motion toward ,itsnormal relationship tto the Icapsta-n member 3,1.-a motion whichvvinvolves the diminution .of `.the air chamber 36 which .ca-n only.occur ,with fa .flow of `air therefrom along vthe .narrow passagway.formed aszabovementioned between the .bore lof .the .coupling membervand liiat ,34, which in `turn ,involes .substantial 4energy dissipa-'Ihus although .the coupling member while .the key remains operated isYin na region where fit will be .struck by therebounding hammer, 4a-4rte-rebound .of `the hammer from it to restrike the reedwhich wouldoccur .with .all highenvelocity key operations in a conventional systemof vthis general `rio-escapefrnent typefis precluded by .the transfer ofthe rebounding hammers kinetic energy to ,the coupling member and theharmless .dissipation from .the coupling member of that energy.

It will be understood that a function .of the `early tenlargement of theair chamber 36 lis 4to prepare ,it ifor its later diminution and that aiunctiono-f .the energy dissipation .during that enlargement is therapid .deceleration of the upwardly moving coupling member, while thefunction of the VVenergy dissipation in .the .later airchamberdiminution is the ultimate one (of .precluding hammer rebound) justoutlined. Y

In a preferred embodiment of the vibrator-exciting action above outlinedI minimize incidental compliances which at the time of impact of therebounding `hammer against the coupling member might yield Yand therebydivert from the coupling member some of the kinetic energy `whichdesirably is transferred from hammer to it for harmless dissipation asoutlined above. Thus I prefer to ,avoid the use of felt or similarbushings at the pivoting point 18 .of 'but-t 1d to flange 15 and to useinstead a relatively large diameter brass pivoting pin; `I prefer' toutilize the vertically still hammer stern described above; I prefer tominimize the compliance of (or even to omit altogether) the thin washerv35 -under the coupling cylinder, and likewise as to the layer 17 above.that member (on the bottom of the hammer butt); I `prefer to omityieldable l,elements from the washer stacks 22 about the pivots 241;Vand I prefer to usea stili material for the keys 2() themselves.

l `In certain .aspects the vibrator-exciting action just outlined hassome similarities to those described in U.S. Patent No. 2,767,608issued`to me October 23, 1956 and in my copending application 'Serial No.376,543, tiled August 26 1953 (which Vis a continuationin-part `of aprier application senat ,.Ne. 292,096, .ined tune 6, 1.952 and sinceabandonedD-but there are several distinctions of importance.

` Attention may now be directed to the mountingot the reeds 10 thetranslation of their vibrations, etc.

The reeds, being .of the fixed-free variety, are of course supported incantilever. The baseof :each reed is preferably'surrounded by a plug 41.of deformable material, and this plug is axially force-ttcd into ahorizontal hole' i42 in an appropriate base member so that the reedeffectively extends horizontally from the base member-the .base memberappearing in section in Figure l being 43. This structure and method ofmounting each reed to a base-.whose advantages comprise exceptionallyrigid, dissipationless and determinate basing of each reed-are describedin detail in my copendingrapplication Serial No. 291,829, 'filed June 5,1952.

The base member 43 does not support all the reeds of the instrument. Inmay copending application Serial No. 284,133, led April 24, 1953, I havedescribed, for an instrument of this general character, the subdivisionof the total base means into a plurality of individual base membersyeach supporting a respective series or group of sequentially tunedreeds; as brought ont in that application, this subdivision is socarried ont that each individual base member has a lowest naturalfrequency of vibration higher than the fundamental frequency of any reedextending therefrom.

In accordance with the present invention a further limitation isobserved: that .the fundamental frequency of vany (in effect, of thehighest-frequency) reed secured to any base member shall be higher thanthe secondpartial frequency of any other (in effect, of thelowestfrequency) reed secured ,to that base member. I have found thislimitation important to avoid the possibility that thefundamental-frequency energy of a reed be dissipated by transfer of thatenergy to second-partial-frequency vibration of another reed secured tothe same base member. Since the ratio of second-partial frequency :tofundamental frequency in a normal reed without special shaping,aperturing or the like is 6.27, and since even with such practises ittends to remain at least 6.0, this specification is readily met forexample by limiting the fundamental-frequency ratio between highestandlowest-frequency reeds secured to any one base member to less than6.0--or, in the tempered scale, to some 3l progressively tuned reeds.

Accordingly in the drawings it will be seen that the -base member 43carries the thirty-one lowest-frequency reeds, Ithe base member 44carries the twenty-four midfrequency reeds, and the base member 45carries the eighteen highest-frequency reedsit ybeing understood thateach base member individually obeys the specification set forth in .thenext-to-last preceding paragraph.

All three base members are individually vibrationally insulated to someextent from the cover 6 by which they are supported and, since they maybe devoid of any vibrational intercoupling other than through the cover,they may accordingly be considered as v ibrationally insulated from eachother to a substantial extent. In connection with their mounting, thereis secured to the bottom of the cover 6 a transverse metal plate 8 abovethe positions to be occupied by the base members. Extending upwardlyfrom each base member through respective oversize holes 9 in the plate 8and into still larger holes 7 in the cover are a pair of studs 46 eachscrewed into the base member, one near each end of the latter. As bestseen in Figure 3, each stud terminates in an enlarged head 47,underneath which may be a metal washer 48. About each stud, between thewasher and plate 8, there is disposed a conically spiralled `compressionspring 49. zOne half of the weight of each base member appears at arespective spring 49, as a compressing force exerted thereon throughlthe respective washer 48, each pair of these springs thus providing.the mounting `of a respective one of the base members.

The studs 46 are so located in the front-and-back dimension that thebase members will have limited tendencies to rock either forwardly orrearwardly, and such tendencies are in any event restrained by strips 50of sponge rubber or the like placed between the base members and plate 8near the front and the back edges of the latter (each base member beingin effect floated by the two respective springs 49 and the sponge rubberstrips 50 just mentioned). There is, however, ample opportunity forsufficient rocking of each base member in response to forces appliedthereto so that each reed is to some extent vibrationally coupled to allother reeds on the same base member-thus simulating the coupling whichexists in the conventional piano between the strings of different notes.iIf desired, this effect may be carried further by deliberatelyintroducing a modest amount (though it should not be too large) ofcoupling between the three base members, over and above that whichoccurs through their mounting to the single cover.

Each of the base members 43, 44 and 45 may comprise a main metalportion, for example of relatively hard aluminum, and a portion ofinsulating material appended to the metal portion. The cross-section ofthe metal portion of the low-frequency base member 43 may be of theshape of an inverted L whose horizontal leg is forwardly directed, is ofappreciable and constant vertical dimension, and is the length orforward extent varying from a maximum at the lefthand extremity, to amoderate value at the righthand extremity, of the member 43and whosevertical leg is of constant height and of thickness varying from aminimum at the lefthand extremity, to a substantial value at therighthand extremity, of the member 43. The crosssection of the metalportion of the base member 44 may likewise be of the shape of aninverted L, and at the lefthand extremity of the base member 44 thedimensions of the legs ofthe L may be similar to those found at therighthand extremity of member 43; proceeding rightwardly, the length ofthe horizontal leg may continue to diminish, while the thickness of thevertical leg may continue to increase, for example so that at therighthand extremity of the base member 44 the cross-section of the metalportion has become a simple thick I. At the lefthand extremity of thebase member 45 its metal portion may have the cross-section of a simplethick I, for example similar to the cross-section of the righthandextremity of member 44; proceeding rightwardly, the upper portion may becut away in front to a small and progressive degree, so that at itsrighthand extremity the metal portion of the base member 45 may have -across-section of the shape of an upright L (as indicated by the solidand dotted lines 45 in Figure l).

It-is in the vertical legs of the base members that the reeds 10 aresecured (through plugs 41 as above described) and from which they extendforwardly. It will of course be understood that with a constant widthand thickness-which I prefer to employ at least for the reeds extendingfrom base members 43 and 44-then for the required progressive tuning thereed lengths will decrease progressively from a maximum at the lefthandextremity of base member 43 to a relatively short length at therighthand extremity of base member 44. I prefer to maintain thelongitudinal mid-points (more precisely, the mid-reed nodal points forthird-partial vibration) of al1 the reeds in straight alignmenttransverse of the instrument-this being so that the hammers, which Iprefer to have strike the reeds in each instance at this position, maybe arranged ina straight transverse lineand I arrange the front surfacesof the vertical legs of base members 43 and 44 in a gradual curveappropriate to that maintenance. Atthe same time the rear surfaces ofthose legs may lie in a transverse vvertical planewhich is permitted bythe thickness specifications set forth in the preceding paragraph.

The progressive decrease of reed length (and with it the curving of thefront surface of lthe vertical leg of the supporting base member) may becontinued throughout the highest-frequency group of reeds (and theirsupporting base member 45) as a sole way of accomplishing the requiredprogressive tuning throughout this group. Because of the relativelyshort reed-length dimension already reached at the righthand extremityof base member 44, however, I prefer to minimize the further reduc- 7tion of reed length throughout that highest-frequencygroup-'supplementing the effect Lof a small length reduction, inlachieving 'the required progressive increase in frequency, by making`the sides 4oli the reeds oblique and the free ends thus narrowerkin-prog-ressively increasing degree toward the rightha-nd extremity ofthe lbase member 45, V'as seen in =Figure l8. A further expedient which`may `be resorted to, in minimizing the reduction of lreed length-throughout this highest-frequency group, is of course a progressive"increase in 4the thick-ness of the reeds.

The insulating "portions of the base members -are designated yas 53, 54and 55, respectively; yeach of lthem may extend forwardly from the upperforward Asurface ofthe respective metal base-member portion. (Each of 53Aand 54 may form a forward projection of the lvhorizontal leg of therespective metal portion of y43 or 44, and 55 may form a yforwardprojectionfrom the lcut-away upper part of v45.) In turn @the forwardpart `of each of the insulating portions 53, 54 and 55 may `convenientlybe cut away at the top (as vseen in AFigure l) vr`to reduce somewhatthat forward-part vertical `thickness. It Lis in this forward part ofthe base-member insulating portions `that the pick-ups aremounted.

Before turning to the translation of the reed vvibrations into 'electricoscillations it kwill be convenient 'to complete the 'description of themechanical portions of the #instrument by reference 'to thetone-terminating dampers. These may be seen in 'Figures l and 9. Thedampers proper, which Vare designated as 56, may each consist of a smallpad of relatively soft material, preferably such as mohair whichpresents an active surface of generally parallel and closely spacedoutwardly extending hairs. Each damper 56 may be secured on the rearupper surface of a 'respective generally vertical spring v57, of whichthe lower portion is secured to a rail 60 described below. Normally eachdamper is lightly biased by its associated spring 57 into contact 'ofits active surface with Vthe free (forward) end of a respective reed 10.When in lthis relationship to that reed it will effectively suppress anysignicant vibration ofthe reed-and if brought into lthat relationship`-to the reed while the reed Yis vibrating `itwillelfectively andpromptly terminate that vibration.

When there is operated the lcey `20 associated with a reed against which-a respective damper 56 is biased, for excitation of that reed, "it isyof course necessary that ythe damper be removed `from contact "with thereed. To accomplish vthis each such -`key maybe provided, somewhatbehind its pivot 21, with 'an upstandin'g heavy-wire arm 58 extending to-a position closely spaced behind the normal position -of themid-portion of the respective damper spring 57, and there foldedoverinto a'short horizon-tal portion 59. -When the key is operated the armportion 59 will 'be rocked diagonally "upwardly Aand forwardly, and inthis movement lwill :impinge against and move `forwardly the respectivedamper Vspring 57, thus placing the respective damper 56 out Vof`contact with the respective reed-a condi-tion l'which `normally"will'bemaintained until release of the key, ywhereupon the damper will returnto contact with `the reed and `will terminate its vibration.

'To .provide the conventional loud pedal action all the dampers maycollectively be removed from contact with their respective reeds. Tothis end the rail 60- whose rear surface may be a gradual -curvcconforming vto the similar `cu-rye formed by the Ifree ends of thereedsmay have a straight forward edge which Ein turn is inset .into -aU-cross-sectionehannel member 61. The assembly 60-6'1 .at .itsextremities may v=be pivoted `to lett- .and rightha-nd standards 62 and-63.

The @assembly 60-61 may be biased about 4its pivots .(countercloekwise-as seen in Figure 11) to a predetermined position by .the combination'(partially seen in Ei-gure 9) :of an .arm [64 extending rearwardly1therefrom,

a spring urging ythe rear extremity of that arm downwardly, and a stop66 limiting .the response of .the arm to that bias-this predetermined.position establishing -the normal position of the rail 60 which waspostulated-in prior-paragraph references lto that rail. The assembly(S0- 6l may `be rocked against its bias (i,e., .clockwise as seen inFigure 1)-thus removing all dampers collectively from contact with theirassociated reeds-by downward llongitudinal movement of va rod 67 which`at its upper extremity is loosely secured -to an arm .68 fextendingforwardly from the channel member 6l. Such downward movement of the rod'67 may be effected in .any convenient manner, most typically by a pedal(not shown) with-'whichits lower extremity may be suitably associated.IDarnpers need -not usually be associated =with1thefvery top 'notes ofthe instrument, and accordingly in its righthand portion 4the dampersystem has been shown as embracing, of the reeds lof thehighest-frequency group (i.e., those extending from base member y445),only fthe most leftward few.

`I have found -it highly desirable inthe production Aof the mostpianistic tones from impulsively excited .fixedfree reeds-whoseupper-partial vibrations (i.e., all above the first, or fundamental) arewell known to be normally inharmonically related to the fundamental-toobserve several Vspecifications (A) To utilize means in the mechanicalsystem which is formed .by the exciting means `and the vibrator tosubstantially eliminate from the translated oscillations an inharmoniccomponent correspondingto one of the lowernumbered of the upper partialsat 'which the reed tends to vibrate-preferably (if the preference underB below be followed) the third parti-al;

(B) To yarrange the mechanico-electrical system which is A'formed Ibythe pick-up Idevice and a portion of the vibrator so that in it is`performed the function of `substantially leliminating from theAtranslated oscillations an inharmonic component corresponding to one ofthe lowernumbered of the upper partials at which thereed tends tovibrate-preferably lthe second partial;

=(C) To arrange the mechanico-electrical system abovementioned so thatby it is performed the function of introducing, into the electricoscillations which it translates from the reed vibrations, a series ofupper partials harmonically Vrelated to the fundamental-preferably aseries which diminishes in composite magnitude l(relative to themagnitude ofthe fundamental) as the vibration of the reed dies awayafter lits impulse excitation; and

(D) To arrange the vmechanico-electrical vsystem abovementioned so thatthe greater deformations ofthe reed attendant `on high-'amplitudevibration, `though involving quite inharmonic upper partials, areutilized to enhance the generation of the abovernentioned harmonicallyrelated upper partiels, as -well Ias to enhance the translation of thefundamental, in the electric oscillations during the very .initialinstants following the impulse 'excitation of ,the reed.

Each `of the `lirst three of these specifications is disclosed in one oranother manner in my cepending appli- .cation Serial No. 169,714abovementioned or my `copending application Serial No. 255,383abovernentioned. 'Iihey are, however, interrelated in -a particularlyfavorable manner in vthe structure of Figures ll gthrough, and with themis combined the very valuable :fourth 'specili- .cation above set forth.

Specifications A and 3, taken together and utilized with respect to thesecond and third reed-vibrationjpartrials., serve .the highly importantfunction of rendering harmless the .significant ones `of the -inharmonic(-i;e., all upper) partials lat which the reed tends to `vibrate-'sincepartials above the third lare normal-ly suiciently'weak so that theirtranslation has a .negligible deleterious effect on .output tone. tatedin other words, they cause the reed-#though actually still excited inthe simple impulsive manner required for a pianistic type of tone-#toapproximate in its effect a vibrator whose vibration is free of partialdevelopment (i.e., whose vibration occurs only at its fundamentalfrequency).

The function just mentionedhighly important since substantialinharrnonic components, especially continuing (as distinguished fromtransient) ones, are intolerable in tones intended to bepianistio--would result, taken alone, in an unusably dull output tone,quite unpianistic `because it would lack the rich development of upperpartials harmonically related to the fundamental which is characteristicof the piano. It is to cure this lack, by creating just such a richdevelopment of harmonic .upper partials, that specification C iscombined with A and B.

It will be convenient iirst to describe the pick-up means and how thestructure meets specifications A, B and C, `and then to bring out theimportance of specification D and how the structure meets it.

Specification C may be met by arranging the pick-up means so that it isprincipally influenced by an edge portion of the reed, which preferablyIwill most fully influence it twice in each cycle of vibration atsubstantial amplitude-it being preferably so arranged that the instantsof greatest inuence, though bicyclic, are never separated by precisely180 degrees (thus avoiding pure double-frequency translation). Referencebeing had to Figures 3, 3a, 4 and 4a, there Will be seen for each reed apick-up means 70. Each such pick-up means may comprise a threadedportion 73 conveniently passing vertically through the forward part ofthe associated base-member insulating portion (e.g., through the forwardpart of 53) and there anchored by means of two nuts 74 threaded on theportion 73 and tightened against the base-member insulating portion, oneon top and the other on the bottom. Each pick-up means may lfurthercomprise a rod portion 72 preferably of reduced diameter forming adownward projection of the `threaded portion, and may finally comprisean active pick-up portion 71-typically in the form of an abruptenlargement of the rod portion at its end into a thin transverse endplate (for example,

of thickness generally similar to that of the associated reed). Seen inplain view of reed and end plate (e.g., in Figure 3a), the end plate 71is closely spaced from an edge portion of the reed'. Vertically, thepick-up means may be so adjusted (by nuts 74) that the end plate 71 isvery nearly at the level of the reed when the latter is in its at-restposition, for example (see ligure) so that its central planeapproximately coincides with the plane of the bottom of the at-restreed.

It is of course desirable that the natural frequency of each pick-updevice be higher than the fundamental frequency of the highest-frequencyreed of the instrument. It is further desirable that the material besoft enough to permit accurate placement of the end plate 71horizontally, relative to the reed, by slight bendings of the rodportion 72, preferably effected with the aid of an appropriate bendingtool.

It will be understood (I) that when the reed moves upwardly the capacitybetweenit and the end plate 71 will progressively reduce; that as thereed moves downwardly from an upward excursion that capacity willprogressively increase, reaching its original value when the reedreaches its at-rest position; that as the reed continues to movedownwardly that capacity will at the very first still further increasesomewhat, to a maximum when the reed and end plate are in alignment (ie,when the central planes of the two coincide), and will thenprogressively decrease; and that as the reed moves upwardly from adownward excursion that capacity will progressively increase, reachingits abovementioned maximum when the central planes of reed and end platecoincide, and will then decrease to reach its somewhat smaller originalvalue when the reed reaches its at-rest position-this analysis of courseassuming that the reed movement is of suiiicient amplitude so that inits downward excursion it proceeds beyond a position of alignment withYthe end plate 71. It will further be understood (Il) that the higherthe amplitude of the reed movement, or vibration, and thus the greaterits velocity in passing its positions of maximum capacityabovementioned, then in the waveform of the capacity variations thegreater will be the Steepness of the approaches to and recessions frommaximum capaci-ty. It will still further be understood (III) that if thereed be vibrating at very high amplitude the intra-cyclic instants ofmaximum capacity-both occurring in the downward-excursionhalf-cycle-Will be separated by almost (but never fully) 180 degrees;that as the amplitude reduces that separation will reduce; and that whenthe reducing amplitude has reached a value only sutlicient (at the peakof the downward excursion) to align the reed with the end plate thatseparation will have reached zero-after which there will be in eachcycle only one instant of maximum capacity.

As will hereinafter more fully appear, with this type of pick-up meansthe translated oscillations are a function of the variations of thecapacity between the reed and the pick-up means. Also, as is wellunderstood, an intracycle departure from pure sinusoidal character, ifrepeated from cycle to cycle (subject to no more than minute amplitudeshifts from one cycle to the next) gives rise to the generation ofpartials which are limited to integral multiples in frequency, or trueharmonics, of the fundamental. Accordingly it is the action described in(I) above (in fully understanding which (II) and (III) above arehelpful) which meets the basic portion of speciiication C-that thepick-up means, in its translating action, introduce into the translatedoscillations a series of upper partials harmonically related to thefundamental. Further, it is the actions `described in (II) and (III)above which meet the supplementary portion of specification C-that theseries of harmonic upper partials diminish in composite magnitude as thevibration of the reed dieS away (magnitude being used in the sense ofamplitude relative to the amplitude of the fundamental).

In the structure specifically illustrated in Figures l through 9 theedge portion of the reed which principally inuences the active portionof the pick-up (i.e., end plate 71) is an internal edge portion, createdfor example by piercing the reed with a somewhat elongated hole 80. Theouter portion (i.e., the portion toward the free extremity of the reed)of the periphery of the hole may, for example and as illustrated inFigure 3a, be of semicircular formation, and it is from this portionthat the active pick-up portion or end plate'71-which in this case mayfor example be circular-is closely spaced. In Figure 3a the dash-dotline 79 may be taken as very approximately illustrating the region,longitudinally of the reed, of average influence of the reed' on thepick-up. To meet specification B this region, as to each reed, may mostdesirably be at the longitudinal position of the node for the secondpartial of the reed vibration. In the case of an unpierced reed ofuniform cross-section this node falls at a position removed from thebase of the reed by approximately 78% (and from the free end of the reedby approximately 22%) of the reed length-and the piercing of the reedappears to make no first-order change of this position, so that apositioning of the hole to bring the line of average influence of readon pick-up at a position removed from the base of the reed byapproximately 78% of the reed length represents a close compliance withspecification B.

It is to meet specification A that the hammers have been called forabove preferably to strike the reed at the mid-reed node for thethird-partial reed vibration-- which node in the case of an unpiercedand uniform cross-section reed falls almost precisely at thelongitudinal mid-point of the reed, and is not substantially altered bythe piercing. Other means of meeting specification A have been disclosedin my copending application Serial No. 169,714 abovementioned; in mycopending application Serial No. 189,345, filed October 5, 1950; now

`11 abandoned and in my VU.S. Patent No. 2,755,697 issued July 24,V1956---consisting generally in rendering integral thenormallynonfintegral ratio between the frequencies ofthe second and iirstpartials ofthe reed vibration, and thus rendering the second partial auseful harmonic of the fundamental. Still `another means of meetingYspecification A yhas been disclosed in my copending application,SerialNa 248,947, tiled September 29, 1951, which is now abandoned .butwhose subject vmatter is vcontinued in vmy `copending application SerialNo. 549,589, filed November ,29, 1955-.consisting generally of .the useof a substantially -softer-than-normal hammer to substan tiallyeliminate the excitation of the upper partials, at least of those `above.the second, .of the reed vibration.

It Will of course be understood that the manner in which the mid-reedvnodal striking of the ,reed meets specification A-i.e., Iin which itsubstantially eliminates from the translated oscillations 4an inharmonic,component corresponding to the third partial at which the reed tends tovibrateis by vsubstantially eliminating the presence of that partial inthe reed vibrations on a selective basis. The difference between thisand each of the other means of meeting specification A above referred towill be apparent.

When -a fixed-free reed is vibrated at high amplitudewhich ,is the caselinitially after strong excitation-at Va plurality of its partialfrequencies the deformation attendant on the upper-partial vibrationcomponents produces -a-n eifective shortening of the reed; this might betermed a temporary or dynamic shortening. Considering the fiirst-partial(or fundamental) vibration, which is the one ofcourse relied on in theabovementioned functioning ofthe structure, this dynamic shortening willtemporarily increase the spacing of the locus of the vibratingfreedextremity from any picloup located just beyondvthat yextremity (such asthe one disclosed in -most ,of the -iigures of my copending applicationSerial No. 169,714 abovementioned). Since the eiciency of translation isa sharp inverse function of such spacing, there takes place during theinitial high-amplitude vibration a very noticeable reduction oftranslation eiciency. Thus, with a pick-up located just beyond the freeextremity of the reed, there can and `does occur an actually observableincrease of amplitude `of the translated oscillations during the earlyinstants after reed excitation, as the dynamic deformation `subsides andthe translation efficiency therefore increases.

This time is one when, in a normal piano, avery noticeable decrement ofthe output sound occurs; indeed, an especiallyhigh.initialdecrement--i.e., decrement during the first few instants of a tone-is astrong .distinguishing feature of piano tone.

By arranging the pick-up means so that the edge portion of the reedwhich most actively iniiuences it is a longitudinally.intermediate edgeportion, or portion other than the free extremity ofthe reed, thedisadvantage just discussed is obviated. Thereby a worthwhileimprovement in respect of tone-inception characteristics is achieved.'The arrangement of the pick-up in .the `strueture .of Figures 1 through9 of course observes this specification (in addition to which it.observes a furtherl one, hereinafter set forth, for the obtainment ofstill further advantage). In meeting the specification of thisparagraph, however, itrwillbe understoodV that the edge portion of thereed which most actively or fully iniiuences the pick-up neednot beaninternal edge portion. Thus .in my copending .application Serial No.255,383 and in Figure y54 .of irny .copending application Serial No.169,714, bothabovementioned, I showed structures in which thatedge'portioniwas a .side-edge region; .such structures ,I now describe.

:Reference `beingihadto .Figure 11, there will be `seen an alternativeconstructiontinfwhch the metal reed base, of approximatelyltr-cross-sectiomis designated .as 115, a treed as 116'and11theassociated' pick-up structure as 117; :it will be understood that thebase 115 will carry other reeds and pick-ups therefor, not herenecessary to show. Each reed may for example be individually clamped inposition between upper and lower largediameter fine-thread socket-headhardened-steel setscrews, 118 and 121 respectively, having slightlyconcave ends resulting in respective small circumferential ridges 120and 122 axially aligned with each other and biting into the respectivereed surfaces thereby to provide -a sharply defined and positivesecuring of the reed; a respective horizontal hole '125, larger than thewidth of the reed, through the-downhanging part of the ibase 115provides clearance space through which .the reed reaches its clampingset-.screws and Within which the forwardly extending or active partofthe reed may freely vibrate; Extending forwardly from the frontsurface ofthe forwardly extending part of the base 115 may be ayrespective insulating bushing 126 internally threaded to accommodate arespective screw 127 by which the respec- Ytive conductive pick-upstructure is secured.

As shown in Figure 12, the pick-up structure may be ypunched from a`sheet of suitable metal and may be generally of inverted-U formation,its downhanging ends 12B-which form the pick-ups proper beingYinternally widened and folded forwardly so that when the pick-.upissecured in position against the ,front of .bushing 12.6, by the screw127 passing through an upwardly .extending central notch in the pick-upstructure, these ends l1128 will be in a plane substantially parallel tothatof the yrespective reed. The pick-ups .(i.e., ends) *128 straddlethat reed, forming therefor a pair of pick-ups,

fand the transverse center line of the pick-ups may -be made to coincidewith the nodal point of the second partial of the reed vibration (whichis typically removed from the secured end of the reed by 78%, and fromthe lfree end by 22%, of the active length .of the reed). Appropriatevertical elongation of the notch 130 permits vertical adjustment of thepick-ups relative to the reedfwhich is illustrated by the fact that inFigure 11 the pick-ups appear as having their bottoms .above the top ofthe reed, whereas in the front view constituted :by Figure 13 theyappear in the more typical position of `partial overlap (vertically)between their thicknesses and that of the reed. Other preciseadjustments of pick-ups relative to reed are readilyl made byappropriate bendings of the pick-up.

An electromagnetic pick-up may be yused if the reeds be of magneticmaterial-'such a pick-up being desirably provided with only a relativelyweak magnetic bias in order to minimize shifting of the frequencyof @theYreed at low amplitudes of vibration due to the magnetic attractionbetween the reed Vand pick-up structure. For effective use in thedevelopment of the series of'upper partials harmonically lrelated to thefundamental, `an electromagnetic pick-up may be placed at the reed edgenear the reed tip; it should develop veryisteep voltage pulses as thereed sweeps past it, and accordingly may have a pole tip very closelyspaced from 'the reed. One type of design utilizes anon-rnagneticallybiased pick-up construction in which the entire coreand pole-piece structure is made of high-quality magneticmaterialsuch-as Permalloy having a very high initial permeability; for a pick-upof this type the biasor magnetomotive force may be provided by the reed(or some otherfs'ource .fclose by), Whose magnetic influence on `thepick-up-will `be modied abruptly by the passage ofthe reed adjacent thepick-up. VFigure 14 illustrates an arrangementl lof an electromagneticpick-.up in which the electrical coils 187 are wound upon individual.cores 188, each core being disposed .between adjacent reeds 190 whichare laterally magnetized as indicated by the polar markings N and S.

It Vwill readily vbe appreciated that in lthe lstructures of Figures l1through13 and of '.Figure14 thelocus `ofl vibration of the-portion ofthe reed which principally modulating, or on a frequency-modulatingbasis.

v 13 influences the pick-up is left unchanged, in effect on the pick-up,by the dynamic shortening of the reed, thereby avoiding any temporarydiminution of the translation efficiency at and immediately after theexcitation of thel reed. I have found, however, that important stillfurther improvement is possible. It is achieved by arranging the pick-upmeans so that the locus of the portion of the reed which principallyinfluences it-instead of being brought further away from it, or leftunchanged, by the dynamic shortening of the reed-is by that dynamicshortening brought closer to it. It is for this reason that I haveemployed, for the portion of the reed which principally influences thepick-up means, an internal edge portion-and have selected for that edgeportion the outer (rather than the inner or an intermediate) peripheralportion of the hole 30. This represents a longitudinally intermediateedge portion specially selected for positive additional advantages.

It will be understood that the effect of this favorable utilization ofthe dynamic shortening of the reed during the early instants followingthe excitation of the reed is not only to enhance the translation of thefundamental (thereby increasing the initial decrement, as is desirable),

but also then to increase the generation of harmonically related upperpartials-since the steepness of the waveform of capacity variation islikewise increased by this utilization. It is so that specification D ismet. This is of especial importance since a distinguishingv feature ofpiano tone, over and above the high initial decrement, is a very initialburst of momentarily accentuated harmonic development.

The pick-up means of Figures 1 .through 9 and of Figures l1 through 13will be recognized as of the capacitative type, and those of Figure 14as of the electromagnetic type, and as to broader aspects of theinvention it will be understood that no limitation as to type isintended. For the capacitative type, in turn, no limitation as tobroader aspects is intended, as between those operating for example on aD.C., on an amplitude- I have preferred, however, to employ thecapacitative type of pick-up means operating on a frequency-modulatingbasis-Le., to employ a system in which variations of the capacitybetween the pick-up means and the reeds, each taken collectively, areused to modulate a high-frequency carrier, which in turn is demodulatedto produce the translated tone-representing oscillations, which in turnmay be amplified and translated into sound by a final audio amplifierand electro-acoustic translating device (not shown).

Reference being had to Figure 10, there will be seen an electronicsystem comprising a pentagrid converter tube 89 such, for example, as a6BA7, of which the second and fourth grids'are interconnected and,by-passed by condenser 105, are supplied with positive potential throughvoltage divider S-104 from a source B-l of plate current, and of whichthe first grid 91 is connected to the upper extremity of an oscillatorcoil 100 through grid condenser 102 and also `to the cathode 90 or tube89 through grid leak 98. The lower extremity of the 'coil 100 isconnected to ground, while the cathode 90 may be connected to a tap 101on the coil 100 appropriate to the setting up of the system 100-90-91-92as a high-frequency oscillator system. In tube 89 the third grid 93 maybe Aconnected to cathode 90 and the fth (or suppressor) grid to ground;in the plate current flowing between plate 96 and the source B1 of platethe oscillations generated by the high-frequency oscillatorabovementoned, amplified by the action of tube 89 and rendered suitable,impedancewise, for feeding into that load.

The several reeds may be electrically interconnected, as byinterconnection of the metal 'portions of the three base members 43, 44and 45 by flexible wires 51, and

current, through the load mentioned below, will appear 14 connected toground. The several pick-up means 70 may be electrically interconnectedin any suitable manner, as by a conductor intertwined around the upperextremities of the threaded portions 73, and connected to a suitable tapon the coil MiG-several such taps being provided so that they may beselected between. These connections place the aggregate capacity,between reeds and pick-up means, in parallel with a selected portion ofthe coil that portion will be selected so that the combination of thatcapacity with the coil will resonate the oscillator systemabovementioned to approximately the desired frequency, fine tuning tothat frequency being accomplished for example by adjustment of avariable iron core 99 associated with the coil.

It will be understood that upon vibration of a reed the aggregatereed-to-pick-up capacity will be varied `oscillatorily,A and that as aresult the frequency of the oscillator system abovementioned will bevaried oscillatorily-i.e., will be modulated by the reed vibrations, itbeing the thus frequency-modulated oscillations which appear in theplate current of the tube 89. The load connected in the plate circuit ofthat tube may be the input of a discriminator-transformer 107 (tuned tothe carrier frequency) of any conventional type, to the output of whichmay be connected in conventional fashion a doublediode discriminatortube 108 and the demodulatedoscillation load system 109 of anyconventional type. It will accordingly be understood that across thedemodulated-oscillation load system 109-i.e., between its upper terminal110 and ground-will appear the electric oscillations translated from thereed vibrations.

Between the terminal 110 and the final amplifier and electro-acoustictranslating device (not shown) the translated electric oscillations maybe passed through a lowpass filter 111-112 to eliminate supersoniccomponents; may be attenuated to any desired amplitude by attenuator113-114; and may be preliminarily amplified by tube 115, shown forexample as a triode-connected pentode with load resistance 116, bleedresistance 117 and cathode .resistancetand condenser 118-119. From loadresistance 116 the oscillations may be applied through condenser 120 toa volume control 121, preferably of the `well-knownamplitude-compensated type illustrated.

From the Ioutput of the volume control 121 the oscillations may be fedto the final amplifier through a network 122 which, in cooperation withthe input impedance lof the amplifier 130, serves to impart thereto afrequency characteristic rising with increasing frequency. Additionallythere may be associated with the output of the volume control, as byshunting thereacross, a resonant circuit (which should be of the seriesvariety for the shunt connection) consisting of variable inductance 123and variable capacity 124, for further shaping of the frequencycharacteristic of the system. I have found that for most pianistic tonesit is desirable that the series circuit 123-124 be resonated at afrequency correspond- 'ing to the fundamental of a tone at or near thebottom effect thus cumulative with that of the network 122. `Interestingand important variations of effect can, however, be achieved by varyingthe resonance of 123-124. The electronic system above described (otherthan the amplifier 130 and the controls proper of elements 121,

l123 and 124) may be mechanically arranged in the form of a compact unit88 which, if desired and as indicated in Figures 1 and 2may bephysically disposed below the cover 6 behind the base members 45 and 44at the treble extremity of the instrument.

Claims to the vibrator-exciting action disclosed herein are not made kinthis application, the same having been 'made in vmy copendingapplication Serial No. 660,787,

led May 22, 1957; likewise claims to the subdivision of base means inaccordance with specifications. set forth above are not made herein butrather in that copending application just mentioned. Furthermore, claimsto structure taking positive advantage of the dynamic shortening of thereed are not made herein, the same having been presented in my copendingapplication Serial No. 673,725, filed July 23, 1957.

While I have disclosed my invention in terms of particular embodimentsthereof, .it will be -understood that unnecessary limitations are notthereby intended, 4since by the disclosure various modifications will besuggested to those skilled in the art. Such modifications will notnecessarily constitute departures .from the scope of the invention,which I undertake Ato express in the appended claims.

I claim:

.1. In combination in an .electricalmusical instrument, .a fixed-freereed, an impulse .exciting means comprising a key actuatedhamrner'adjacent the' reed selectively engageable with the individualreed for setting it into Adecadent free vibration, and an electrictranslation pick-up adjacent the reed, said pickup having atoneproducing portion located alongside and being vibratorily passed by alongitudinally intermediate edge portion of the reed and being ofan-etfective thickness, inthe direction of reed vibration, smaller thanthe high-amplitude stroke of-said edge portion -of the reed.

2. In combination in anelectrical musical instrument,

a fixed-free reed, an impulseexciting means comprising a key actuatedhammer adjacent thereed.selectivelylengageable with the individual reedforsetting it into Vdecadent free vibration, andan electric translationpick-up adjacent the reed, said pickup having a tone producing portionlocated alongside and .being vibratorily passed by a longitudinallyintermediate edge portion of the reed, being of an eiective thickness,`in the direction `of reed vibration, smaller than the-high-amplitudestroke ofsaid edge portion of the reed, and being oiset in saiddirectionfrom effective alignment with the rest position ofthe reed.

3. The combination claimed in claim 1, wherein said edge portion of thereed is located substantially at ia node for .a lower one of the upperpartials ofthe free vibration of the reed. i i Y 4. The combinationclaimed rin claim 1, wherein said edge portion of rthe reed issubstantially nodal `for the second partial of the kfree vibration ofthe reed.

5. The combinationclairned in claiml, wherein said edge portion -of thereed is substantially nodal for Ythe second partial of the freevibration of the reed and wherein, in the direction of reed vibration,said pickup portion has an effective mid-pointoffset from the restposition of the eifective mid-point of said vedge portion of the reed. i

6. In combination in anelectrical musical instrument, a mechanicalsystem comprising a fixed-free reed and an impulse exciting meanscomprising a key actuated harnmer adjacent the reed selectivelyengageable with the .findividual reed for setting it into decadent freevibration, an electric translation pick-up adjacent the reed, saidpickeup havinga tone producing portion located alongside and beingvibratorily passed by a longitudinally intermediate edge portion of thereed and being of an effective thickness, in the direction of reedvibration, smaller than the high-amplitude stroke of said edge portionof the reed, and means comprised in said mechanical system for at leastsubstantially eliminating from the free vibration of the reed ailowerone of `itsnormally present upper partials.

7. The combination claimed in claim 6, wherein said edge portion of thereed is substantially -nodal -for 4 another lower one of the lupperpartialsrof the free vibration of the reed.

8. In combination vin an electrical musical instrument,

a ,ixed-freerced, an impulse Iexciting means adjacentthe reedandeffeotive thereon substantially ata node yfor one of the two lowestof the upper partials of the free vibration of the reed for setting thereed into decadentfree vibration, and an ,electric translation pick-up-adjacent the reed, said ,pickup having a tone producing portion locatedalongside and being vibratorily passed by alongitudinally lintermediateedge portion of the reed and being of an effective thickness, in thedirection of reed vibration, smaller than the lhigh-amplitude stroke ofsaid edge portion o-f the reed, saidedge vportiono'f ,the reed 4beingsubstantially .nodal for the other offsaid two lowest upper partials. l

9. In combination in a musical instrument, a iixed-freereed,`singleimpulse exciting means comprising akey actuated hammerselectively engageable with ,the individual reed for setting it intodecadent .freevibratiorn a mechanico-electrical system consisting of aportion of the reedand pick-upimeans associated with and influenced 'bysaid portion -for translatinglelectric oscillations from the reedvibrations, 4means comprised in said mechanico- `electrical system foratleast substantially eliminatingfrom said oscillations aninharmoniccomponent corresponding toa lowerone of the Aupper partials V at whichthe reed `tends to vibrate, and means `also comprised in saidmechanico-electrical system `for introducing into the oscillationstranslatedfrom v`the fundamental reed vibrations Va series of upperpartials harmonically related thereto.

110. `combination in a musical ins trument, a mechanical systemcomprising axed-free reed and single-impulse exciting means for settingit into decadent free vibration, a mechanicofeleotrical systemconsisting of aportion of said reed and pick-up means associated withand V,inuencedby said portion for translating electricoscillations'frornthe reed vibrations, means comprisedin `Said Amechanical system for atleast substantially eliminating from said oscillations an inharmoniccomponent corresponding to one ofthe two lowest ofthe upper partials atwhich the reed tends to vibrate, means comprised in saidmechanico-electrical system for at least substantially eliminating fromsaid oscillations an inharmonicvcomponent corresponding to the other ofsaid two partials, .and means also comprised in saidmechanicofelectrical system for introducing into the oscillations`translated fronithe fundamental reed vibrations ,a Aseries of upperpartials Yharmonically related thereto.

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